1. Field of the Invention
The present invention relates to a projection apparatus capable of changing a projection lens.
2. Description of the Related Art
Conventionally, there is a projection apparatus that is capable of changing a projection lens (hereinafter, referred to as a lens). However, an appropriate projection setting in accordance with characteristics of the lens is not considered. Therefore, the readjustment in accordance with the characteristics of the lens after changing the lens, particularly the setting related to a lens shift amount is left to a user. For example, Japanese Patent Laid-Open No. 2001-215610 discloses a method of detecting whether or not a shift amount between an image axis that is a center of an image and a lens optical axis that is a center of the lens is over a certain value using a distance sensor.
However, in the detection method disclosed in Japanese Patent Laid-Open No. 2001-215610, there is a possibility that projection light after changing the lens does not normally enter the lens even when a position of the lens is in a normal range before changing the lens. As a result, there is a case where an image is not formed on a screen and any screen message is not displayed. Therefore, a reference position needs to be set for each lens so that an appropriate projection is possible.